How do you look at the phenomenon of elementary school students having a lot of homework?

Some teachers especially like to let children carry out a lot of copying and writing repetitive work, this kind of homework is really not necessary, a lot of copying and writing can not improve the child's ability to learn and understand, but instead of taking up a lot of the child's time. Moreover, some children write slowly and get tired easily. I agree with the teacher to assign homework, but the homework should have a small amount of copying, and then add a part of thinking or reading homework for the child, so that the child to use his brain to think, not just to copy.